1. Field of the Invention
This invention relates to the field of photography and, more particularly, to a photographic apparatus including an exposure counter which communicates motion to an exposure actuating means whereby the exposure actuating means assumes a definite series of positions.
2. DESCRIPTION OF THE PRIOR ART
It is customary to provide photographic apparatus with an exposure counter so as to convey certain information to the user regarding the number of exposures which have been made or which remain in a film assemblage located within the photographic apparatus. Exposure counters generally include an indicia-bearing member having characters thereon which are sequentially presented at a viewing station, usually a window, in the apparatus for conveying this information to the user. The characters may be sequentially changed by an indexing system coupled to a film advancing apparatus which in turn is manually operated by a hand crank located on the camera as shown in U.S. Pat. Nos. 2,608,922 and 2,552,275. Operation of the hand crank advances a film frame into position for exposure and simultaneously indexes the exposure counter to change the character present at the viewing station. Needless to say, manual operation of the crank leaves something to be desired. Furthermore, exposure counters are unduly complicated in construction and operation, and are often positioned in locations within the apparatus having limited accessibility, thereby making it more difficult to reset them to their starting position subsequent to the exposure of the last film unit or frame in the film assemblage. One solution proposed to improve the problem of resetting the exposure counter is described in U.S. Pat. No. 2,813,469, namely, an arrangement whereby opening the camera's door will automatically reset the camera's exposure counter to its starting position. However, opening the camera's door is not necessarily connected with the act of providing the camera with a fresh supply of film and therefore does not necessarily ensure that the counter will be properly oriented prior to the next exposure. For example, after one or more film units have been exposed, should the camera's door be opened for purposes of viewing the film container to ascertain if it is correctly positioned within the camera or for inspection of one of the components of the camera, such as the processing rollers in a camera of the self-developing type, the counter would be automatically reset thereby resulting in the exposure number of the counter being out of phase with the number of the next exposure.
U.S. Pat. No. 3,653,313 describes an exposure counter for use with a single-lens reflex camera which solves the problem of resetting exposure counter by automatically resetting the camera's counter upon removal of a flim container from within the camera. However, the exposure counter is coupled to a reflecting member or mirror and is sequentially advanced in response to movement of the reflecting member between a raised exposure position and a lowered viewing position. In order to utilize the pivotal movement of the reflecting member to index or rotate the exposure counter, a relatively complex system including a plurality of pivotally mounted pawls and cam surfaces interact to accomplish the desired result of indexing the exposure counter. Therefore, the indexing and resetting of the exposure counter is substantially dependent upon each member of the system being properly located and coupled to an adjoining member such that the previous movement of one member is sufficient to displace a second member in contact therewith, originating with the reflecting member operating to initiate movement of the counter in the indexing mode and terminating with a cantilevered spring, one end of which displaces one of the pawls during removal of a film container thereby enabling the exposure counter to reset itself in the starting position.
An improved exposure counter employing relatively few moving parts is described in detail in a copending application Ser. No. 554,764, filed on Mar. 3, 1975 in the name of Bruce K. Johnson et al, entitled "Exposure Counter for an Automatic Camera", now Pat. No. 3,984,852. The exposure counter disclosed therein includes a rotatably mounted, indicia-bearing cylinder having characters arranged around an outer periphery thereof which is sequentially advanced during each photographic cycle of an automatic camera so as to convey information to the user regarding the number of exposures which have been made or which remain in a film cassette stored within the camera. The cylinder is sequentially advanced or indexed by a pin extending from one side of a gear which rotates one revolution during each photographic cycle of the camera. During each revolution of the gear, the pin engages one of a plurality of teeth supported upon a first side of the cylinder thereby advancing the cylinder and changing the character presented to the user. The exposure counter is further provided with a pawl which prevents movement of the cylinder in a predetermined opposing direction to the advancement of the cylinder by ratcheting into engagement with one of a plurality of notches arranged upon a second side of the cylinder subsequent to the advancement of the cylinder. Upon the removal of a spent film container or cassette from within the camera, the pawl moves out of engagement with the cylinder thereby allowing the latter to automatically reset itself to a starting position.
However, the aforementioned exposure counters have been limited to conveying information to the user as to the number of exposures which have been made or which are available for use in the camera. Previously, the starting and end positions have only conveyed to the user that the film chamber was full or empty. The motion of the counter therebetween during the sequential advancement or the resetting thereof has not generally been utilized to provide the camera with any additional operational advantages or desirable and serviceable features. Therefore, the inclusion or exclusion of an exposure counter within a camera has often been determined by weighing the advantage of providing such information on the camera against the degree of mechanical difficulty and cost of including such a convenience within a limited area of a compact housing of the camera, particularly in the design of a low-cost, light-weight automatic photographic apparatus.